Mouse response to influenza immunosomes

Immunosome preparations consisting of surface glycoproteins, extracted from five influenza virus strains and anchored onto performed liposomes, were tested in mice. Serum antibody responses were essentially similar to those elicited by whole virus vaccines and higher than responses induced by subunit preparations. Antibody titres were assessed by haemagglutination-inhibition technique. Survival of mice immunized with 6 micrograms haemagglutinin of attenuated, inactivated, subunit or immunosome A/Aichi/2/68 vaccines and later challenged with variants of the same subtype was also assessed. All vaccine preparations induced similar percentage survival when mice were challenged with variants prevalent from 1968 to 1977. However, the attenuated vaccine induced a significant higher protection level against the 1979 variant.